Evinrude 4 hp Lightwin prop/shear pin issue

scottybk

Cadet
Joined
Nov 9, 2010
Messages
9
I have a 1971 Evinrude Lightwin 4 hp.

I broke the prop's shear pin on a rock recently for the first time since I've had it. I got replacement shear pins from a boat dealer, and hit another rock right after putting the new pin in.

What happened this time is that the new pin did not break, but instead cut a circular groove in the inside of the plastic prop by not snapping off inside the notches. Now the prop is trashed because the notches will no longer "hold" the pin since the plastic is gouged in a complete circle inside the prop.

This prop design strikes me as incredibly poor. The little "notches" that act as keepers for the shear pin ends are only about 1/8 inch or so deep. They also are not lined with a metal sleeve or anything like that. My hunch is that there isn't enough "leverage" to break the pin, so it just grinds it's way out of the notches by gouging the plastic.

Anyone have any ideas/advice? A new prop for this thing is expesnive, and I don't want to trash another one. As I said, it seems like a poor design...are the replacement props made any better?
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Evinrude 4 hp Lightwin prop/shear pin issue

I wonder if there are aluminum props and plastic and the plastic uses a different pin.
Put a bolt through the hub into the grove forming a stop for the pin.
 
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